Currently, there are generally two methods of providing the business of communication service level for users: one is implementing the business of communication service level based on the user category; the other is implementing the business of communication service level based on that the calling user additionally dials the access number prefix.
Regarding the first method, the operator classifies the mobile users in the mobile communication networks such as GSM. Each user category corresponds to a certain level of priority. The corresponding user category is set into the User Data Management System by the operation of the Customer Service System (or, the Business Operation Supporting System). The equipment of the Core Network or the Switch Network acquires the mobile user's user category from the User Data Management System during the process of the Mobility Management to the user. When the mobile communication network provides the communication services for the mobile user as calling service or called service, the equipment of the Core Network or the Switch Network comprehensively analyzes the user category of the mobile user and the support capability of the currently used mobile terminal, and then informs the equipments of the Wireless Access Network of the relevant information of the communication service level (such as the channel type, encoding rate and so on) corresponding to the user. According to the principle that allocating different ways of channel encoding for different priority levels, in high-load condition, the equipment of the Wireless Access Network will still allocate corresponding mobile network resources according to the relevant information of the user's communication service level. For high-level users, even in the situation of the Wireless Access Network resources strain, the mobile communication network will also provide priority for wireless access business with high-speed coding rate. The flowchart of this method is shown as FIG. 1.
Although this method can implement providing the business of communication service level for users, shortcomings are still exists. After a user is set to be a certain user category, when he is on calling as the calling party or the called party, the communication can only be conducted according the communication service level corresponding to the user category. However, for the user, calls with different communication service levels are needed under different circumstances. If the user category is to be changed, the operation by the Customer Service System or the Business Operation Supporting System should be conducted in the User Data Management System. The communication service level can't be real-timely set according the user's need or aiming at each call.
Regarding the second method, the operator sets some special access numbers. The calling user can choose whether to dial the above access number as the called number's prefix when he dials the called number. As shown in FIG. 2, if the calling user doesn't additionally dial the above access number prefix before he dials the called number, the network equipment on the calling side will continually connect this call to the TDM Carrier-based communication network (or called Circuit-Switched Network) when it receives the call request of the calling user. For this call, the communication service network between the network equipment on the calling side and the called side is the Circuit-Switched Network; if the calling user additionally dials the above access number prefix before he dials the called number, it will continually connect this call to the Packet Network Carrier-based (IP network or ATM network and so on) communication network corresponding to the access number prefix dialed by the calling user after the network equipment on the calling side receives the call request of the calling user. For this call, the communication service network between the network equipment on the calling side and the called side is the Packet Network Carrier-based communication network.
For the situation that there are several Packet Network Carrier-based communication networks which can provide services between the equipment on the calling side network and that on the called side network, the operator will correspondingly set multiple access number prefixes. After receiving the call request of the calling user, the equipment on the calling side network continually connects this call to the Packet Network Carrier-based communication network corresponding to the access number prefix currently dialed by the calling user.
By detecting whether the access number prefix is additionally dialed in the called number dialed by the calling user and which access number prefix is dialed, the equipment on the calling side accordingly chooses the communication service network between it and, the equipment on the called side network. As different communications service networks may have different communication service qualities, the calling user can choose the communication service level for this call by different ways of dialing (such as whether additionally dialing an access number prefix before dialing the called number or which access number prefix to dial additionally and so on).
However, this method also has its shortcomings. For the situation that communication services between the equipment on the calling side network and the called side network are provided by the same communication network, according to this method, the calling user can't choose the communication service network for this call by different ways of dialing (whether the access number prefix is additionally dialed before the called number dialed by the calling user and which access number prefix is dialed) so that the communication service level for this call can't be chosen by different ways of dialing.
For the situation that the communication services between the calling terminal and the equipment on the calling side network are provided by only one communication network and the situation that communication services between the called terminal and the equipment on the called side network are provided by only one communication network, according to this method, the calling user can't choose for this call the communication service network between the calling terminal and the network equipment on the calling side or between the called terminal and the network equipment on the called side by different ways of dialing, so that by different ways of dialing, the communication service level on the calling side, and on the called side can't be chosen for this call.